Apparent equilibrium temperature

The similarity between the apparent equilibrium temperature equation and the closure temperature equation can be seen by comparing Equation 5-125 and Equation 5-77b by letting Tae and Tc be equivalent, Xr (reaction timescale) and x (diffusion timescale) be equivalent, and G = 2, the two equations become the same. 

Given measured species concentrations for a homogeneous reaction in a rock, cooling rate at Tae can be found as follows if the equilibrium constant K and the forward reaction rate coefficient k as a function of temperature are known. First, the apparent equilibrium temperature is calculated from the species concentrations. Then kf and kb at Tae are calculated. Then the mean reaction time Xr at Tae is calculated using expressions in Table 2-1. From x, the cooling rate q at Tae can be obtained using Equation 5-125. Two examples are given below. 

Temperature non dimensional time Apparent equilibrium temperature Closure temperature Glass transition temperature Time... 

It is widely accepted [52-56] that generic gasifier models are set up using history matching, meaning that experimentally measured residual carbon and individual deviations from equilibrium for selected reactions are specified in the model. Equation (5.31) introduces a so-called approach temperature Tapp, which is defined as the difference between the measured physical gas temperature Tp of the process and the associated, calculated apparent equilibrium temperature Teq, according to the gas composition see Figure 5.6, which describes the individual deviation from equilibrium. 

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